The invention concerns a module with an adjustable heat coefficient and embedded photovoltaic solar cells or a heat absorbing layer. Multiple modules connected together and laid as a building facade or a skylight roof will be used as an outer envelope of a building, in particular for use as a curtain wall or roof element, with at least one outer pane facing towards the incident light, consisting of at least one inner layer of solar cells or light absorbing element arranged at a distance behind outer plane and a second preferable transparent element arranged in a distance behind the solar cells. This arrangement is producing at least two enclosed cavities; one in front of solar cells plane and the second behind the solar cells or light absorbing plane, producing interspaces. Sunlight penetrating through first transparent layer is absorbed by second solar cells layer to produce electricity and heat at ratio of about 15% electricity and about 60% heat, it is the purpose of this invention to provide the interior of building with smart energy harvesting of both heat and solar electricity—this is achieved by controlling the U value of the two enclosing cavities by heat convection. Two cylindrical fans installed inside the two cavities on their outer perimeter frame, without obstructing the transparent plane facing the sun, will independently control the air convection through the cavities thus controlling the heat flow from solar cells layer through the air cavity.
Modules of this type will be generally assembled as a curtain wall or skylight producing a building envelope. For such applications the modules are mechanically attached to the buildings' inner frame, and the electrical inter connections are provided by separate connectors.